Keying switch assembly

ABSTRACT

A keying switch assembly operable by means of a key includes a stationary contact member, an elastically bendable contact member having a fixed end and a movable end which is selectively operable to contact the stationary contact, and a flexible shock absorber attached to the bendable contact member for reducing shock noises. An actuator strikes against the shock absorber upon operation of the key so as to cause the bendable contact member to be silently bent, so that the movable end thereof contacts the stationary contact member.

United States Patent Inventor Seiji Nakada Hamamatsu-shi, Japan Appl.No. 878,061 Filed Nov. 19, 1969 Patented Aug. 17, 1971 Assignee NipponGakki Seizo Kabushiki Kaisha Nakazawa-cho, Shizuoka-ken, Japan PriorityNov. 21, 1968 I Japan KEYlNG SWITCH ASSEMBLY 9 Claims, 4 Drawing Figs.

US. Cl 200/166 l-l lnt. Cl l-l0lh 1/50 Field of Search 200/ l 66 H,

[56] References Cited UNITED STATES PATENTS 2,802,076 8/1957 Carlson etal 200/166 H X 3,255,326 6/1966 Schwartz et a] ZOO/86.5 3,388,229 6/1968Lyvang ZOO/166.1

Primary Examiner-H. 0. Jones Attorney- Flynn & Frishauf ABSTRACT: Akeying switch assembly operable by means of a key includes a stationarycontact member, an elastically bendable contact member having a fixedend and a movable end which is selectively operable [to contact thestationary contact, and a flexible shock absorber attached to thebendable contact member for reducing shock noises. An actuator strikesagainst the shock absorber upon operation of the key so as to cause thebendable contact member to be silently bent, so that the movable endthereof contacts the stationary contact member.

PATENTED AUG] 715m FIG.

FIG 2 FIG. 3

KEYING SWITCH ASSEMBLY This invention relates to a keying switchassemblyparticularly adapted for usein anelectronic musical instrument.

As generally known, a keying switch assembly comprises one or moreswitch units, each of which involves'a stationary contact member, anelastically bendable contact member, and

an actuator for striking against said latter contact member.

For a musical instrument, however,"theremust beavoided'as' much aspossible the shock noises generated by the actuator striking against thebendable contact member and by the con'- tact between the stationarycontact member and the elasti cally bendable contact member. It isfurtherdemanded thatthe-flexibility of the bendable contact memberbe'maintained 1 even if a shock absorber is attached to the bendablecontact member in order to avoidthe generation of thenoise.

An object of this invention is to provide akeying switch assembly soimproved'as to avoid the generation of noises."

Another object of this invention is to provide --a keying switchassembly so improved as to avoid the generation 'of noises, and at thesame time maintaining an elastically bendable contact member with thesame degree of flexibility as occurs in thecase where the contact memberis not provided with a shock absorber.

SUMMARY OF THE INVENTION According to this invention, the keying switchassembly comprises one or more switch unitsgeach of which comprises astationary contact member, a leaf-shaped elastically bendable contactmember, oneend thereofbeing fixed and the other end thereof beingmovable, said elastically bendablecontact member 9 being selectivelymovable to contact with-said stationary-contact member 7; a thinshock-absorbing plate attachedto an intermediate position of thebo'dy ofthe bendable contact member and .an actuator actuated by the vkey andstriking against the shock absorber to cause the bendablecontact memberto contact the stationary contactmember.

According to a further feature of this invention the shock:

absorbingqplate has a plurality of parallel-spaced grooves- FIG. 2 is aperspective view of the essential parts of said keying switch assembly;

F IG'; 3 is a transverse cross section of a shock absorber in: volved insaid keying switch assembly; and

FIG. 4 is a side view of another embodiment of a keying switch assemblyof the present invention.

. FIGS. 1 to 3 indicate a keyingswitch assembly comprising one switchunit in corresponding relationship with each of a plurality of keymembers. Each of said key members 1 is swingably supported by causing aV-shaped'groove formed at the rear endthereof to engage with the upperedge of a vertically disposed supporting plate 2. Said supporting plate2 has a rearwardly bent lower portion, and a-coiled spring member-3bridges the rear ends of said supporting plate and key member. Saidsupporting plate 2 is'attachedto the rear end of a key bed frame 4,2 thelower side of which are disposed first and second supporting members 5and 6 of electric insulatingmember 1 and extending parallel to eachother. A leaf-shaped elastically bendable contact member 9 is attachedto the lowerend of said'second supporting member 6 and forwardly extendstherefrom in a mannerto cause its forward end-portion to contact thecontact member 8; Said contact member 9 is preferably made of phosphorbronze or nickel silver. Arranged' above and parallel to said contactmember 9 is an elastically bendable supporting member 10 whichforwardlyextends from said supporting member 6. An actuator 11 formed as a shortbarmember is attached to the forward end of said supporting member 10and vertically'extends through a bore 12 formed in the bodyof said keybed frame 4.

A thin shock-absorbing plate 13 is attached to an intermediate positionof said bendable contact member 9. Said absorbing plate 13 consists of aflexiblemember, for example, of soft synthetic resin or rubber, andimproved so as to maintain the flexibility'of the bendable contactmember 9, thereby permitting said' bendable contact member to be bentthrough said absorbing plate 13.Said absorbing plate 13 is preferablyprovided with a dovetail groove 13' opening'at the lower side thereofandextending in a longitudinal direction of the bendablecontactmember-9. Said bendable contact member 9 has a dovetail cross section tobe fitted into said dovetail groove. The contact member 9 is thuseasilyand firmly engaged in the dovetail groove 13' of the absorbingplate 13 even after the contact member 9 is attached to the supportingmember 6. Said shock absorber 13 preferably has a plurality of parallelspaced grooves 14 so as to maintain the same flexibility as occursin thecase where said contact member 9 is not provided stanceyof soft rubberwhich is attached to the lower portion thereof and abutting against thetop of said actuating bar 11 when the key member is pushed down.

in operation, the swinging'motion of 'said key member 1 causes theactuator 11 noiselessly to strike against the shock absorber l3 and thusbend the body of said-bendable contact member "until the forward endportion of said contact member9contacts the stationary contact member 7so as to be electrically connected therewith. When the force applied tosaid key member is released, said key member '1 automatically returnedby the action of the spring member 3 so that the actuator 11 is removedfrom the upper surface of said shock absorbing plate 13 by the reactionof said supporting member ID and the contact member 9 is returned to theoriginal position byits own reaction, electrically disconnecting thecontact members 7 and 9 from each other. Although the shock absorber 13is attached to the bendable contact member 9, it will not so actdue toits thin and flexible body as to obstruct the contact member'9 frombeing fully bent when the key is lightly touched by the player.

FIG. 4 indicates another embodiment of the keying switch assemblywherein many switch units corresponding to one key memberare arranged insuch'a manner that elastically bendable contact members 9a, 9b and 9cinvolyed in said switch units respectively are operated only by a commonactuating member 11d, and there is attached a flexible shock absorber13a to each of said contact members. in this case, said flexible shockabsorber 1311 has a protrusion 16 integrally formed on theupper portionthereoflsaid protrusion 16 contacting the lower surface of the adjacentcontact member positioned there'above, and theuppermost protrusion beingin abutment against the lower end of the actuating member lla. Theheight of the shock absorber 13a is, at the protrusion portion,substantially equal to the distance between the adjacent two of theelastically bendable contact members.

What I claim 'is:

l. A keying switch assembly operated by a key comprising:

a stationary contact member (7);

a leaf-shaped elastically bendable contact member (9), one end thereofbeing fixed and the other end thereof being movable, said elasticallybendable contact member (9) being selectively movable to contact withsaid stationary contact member (7);

a shock absorbing member (13) of flexible material attached to saidelastically bendable contact member (9) at a position thereofintermediate said fixed and movable ends; and

an actuator (10, ll) actuated by said key (1) and striking against saidshock absorbing member (13) to bend said elastically bendable contactmember (9) into contact with said stationary contact member (7).

2. The keying switch assembly claimed in claim 1 in which said shockabsorbing member (13) is made of rubber.

3. The keying switch assembly claimed inclaim l in which said shockabsorbing member (13) has a dovetail groove (13) extending in thelongitudinal direction of said elastically bendable contact member (9),and said elastically bendable contact member has a dovetail crosssection which is fitted into said dovetail groove. I

4. The keying switch assembly claimed in claim 1 in which said shockabsorbing member (13) has a plurality of parallel spaced grooves (14)formed at the lower portion thereof and extendingin thetransversedirection thereof.

5. The keying switch assembly claimed in claim 3 in which said shockabsorbing member (13) has a plurality of parallelspaced grooves (14)formed at the lower portion thereof and extending in the transversedirection thereof.

6. The keying switch assembly claimed in claim 1 in which said shockabsorbing member (13')-has a protrusion (16) integrally formed on theupper portion thereof.

7. The keying switch assembly claimed in claim 1 wherein said stationarycontact member (7) extends transversely of said elastically bendablecontact member (9);.and said shock absorbing member (13) is disposedbetween said stationary contact member (7) and said fixed end of. saidelastically bendable contact member (9). v

8. The keying switch assembly claimed in claim 1 wherein said actuator(10,11) comprises an elastically bendable support member (10) having oneend fixed, and an actuator member (11) connected to the other end ofsaid elastically I bendable support member (10).

9. The keying switch assembly claimed in claim 1- wherein said shockabsorbing member (13) is generally in the form of a plate. a

1. A keying switch assembly operated by a key comprising: a stationarycontact member (7); a leaf-shaped elastically bendable contact member(9), one end thereof being fixed and the other end thereof beingmovable, said elastically bendable contact member (9) being selectivelymovable to contact with said stationary contact member (7); a shockabsorbing member (13) of flexible material attached to said elasticallybendable contact member (9) at a position thereof intermediate saidfixed and movable ends; and an actuator (10, 11) actuated by said key(1) and striking against said shock absorbing member (13) to bend saidelastically bendable contact member (9) into contact with saidstationary contact member (7).
 2. The keying switch assembly claimed inclaim 1 in which said shock absorbing member (13) is made of rubber. 3.The keying switch assembly claimed in claim 1 in which said shockabsorbing member (13) has a dovetail groove (13) extending in thelongitudinal direction of said elastically bendable contact member (9),and said elastically bendable contact member has a dovetail crosssection which is fitted into said dovetail groove.
 4. The keying switchassembly claimed in claim 1 in which said shock absorbing member (13)has a plurality of parallel spaced grooves (14) formed at the lowerportion thereof and extending in the transverse direction thereof. 5.The keying switch assembly claimed in claim 3 in which said shockabsorbing member (13) has a plurality of parallel-spaced grooves (14)formed at the lower portion thereof and extending in the transversedirection thereof.
 6. The keying switch assembly claimed in claim 1 inwhich said shock absorbing member (13) has a protrusion (16) integrallyformed on the upper portion thereof.
 7. The keying switch assemblyclaimed in claim 1 wherein said stationary contact member (7) extendstransversely of said elastically bendable contact member (9), and saidshock absorbing member (13) is disposed between said stationary contactmember (7) and said fixed end of said elastically bendable contactmember (9).
 8. The keying switch assembly claimed in claim 1 whereinsaid actuator (10,11) comprises an elastically bendable support member(10) having one end fixed, and an actuator member (11) connected to theother end of said elastically bendable support member (10).
 9. Thekeying switch assembly claimed in claim 1 wherein said shock absorbingmember (13) is generally in the form of a plate.